This invention relates to hair curling instruments. More particularly the invention relates to hair curlers which include a handle having a rod-like, electrically heated tube at one end on which a strand of hair is wound, and a thumb-operated clamp to secure the hair on the tube for treatment with heat and/or steam.
It is well known in the prior art to employ steam dispensing hair curling instruments constructed generally as described above in the treatment and setting of hair. Representative prior art devices are disclosed by Barradas, U.S. Pat. No. 3,768,491; Brown, U.S. Pat. No. 3,610,259; Van Droogenbroek, U.S. Pat. No. 3,220,421; Jones, U.S. Pat. No. 2,880,299; and Cannon, U.S. Pat. No. 2,254,266.
Many of the prior art devices however are deficient in one or more respects. For example, one of the major problems in the prior art is that liquid tends to leak outwardly through the steam passage holes when the curling instrument is oriented in certain positions. In part, to remedy this difficulty some of the prior art devices utilize an absorbent wick for receiving the treatment liquid. This approach, which only partially solves the leakage problem, unnecessarily limits the capacity of the fluid vaporization chamber and adds to the complexity and cost of the device.
Another problem with some of the prior art devices relates to the fluid injection systems utilized therewith for delivering liquid to the vaporization chamber. To inhibit fluid leakage complex mechanical valves employing springs, nozzles, or the like are sometimes utilized. As a result manufacturing costs are increased. Additionally the prior art fluid injection systems often comprise protuberant parts which contribute to structural dissymmetry and interfere with hair curling.
Furthermore, some prior art fluid injection designs may increase electrical shock hazards for the user. The construction of some prior art hair curlers makes it possible, if not likely, that the user will attempt to fill the device with liquid while it is still connected to a source of electricity, thereby exposing himself to a serious electrical shock hazard.
It is accordingly a fundamental object of this invention to provide a steam dispensing hair curling instrument which is adapted to prevent the passage of water through the associated steam ejector holes.
It is another object of this invention to provide a hair curling instrument of the character described which does not utilize an absorbent wick to prevent the said leakage of fluids.
Another object of this invention is to provide a hair curling instrument having a fluid injection system which does not utilize complex mechanical valves.
Yet another object is to provide a hair curling instrument of the character described with a generally symmetrical fluid injection structure which does not interfere with the wrapping or curling of hair.
A still further object of this invention is to provide a hair curling instrument of the character described with a fluid injection structure having a detachable fluid reservoir which may be filled with liquid without subjecting the user thereof to electrical shock hazards. In the present invention the aforementioned syringe must be detached from the device for filling with fluid, so that shock hazards are reduced by the resultant electrical isolation.
The preferred hair curling instrument of the present invention has a generally cylindrical handle with a rod-like steam dispensing tube attached thereto. The steam dispensing tube comprises a cylindrical heater tube, which houses an electrically resistive heater wire, and a cylindrical outer shell, into which the heater tube is axially inserted. The handle is channeled to receive electrical conductors which extend therethrough to energize the heater wires and produce heat. An annular steam chamber is defined in part between the walls of the heater tube and the cylindrical outer shell. Fluid is injected into the steam chamber by a syringe which is removably attached to the end of the steam dispensing tube. The syringe comprises a hollow, preferably molded rubber squeeze bulb which is symmetrically tapered to conform to the profile of the steam tube to thereby minimize interference with hair curls. Since the syringe must be removed from the steam tube in order to be filled with liquid, potential electrical shock hazards are significantly reduced.
Steam or vapor produced when liquid contacts the heater tube escapes through a plurality of steam passage holes which are provided in the outer shell of the steam dispensing tube. An insert or baffle is sandwiched between the heater tube and the steam tube shell to inhibit the passage of water through the adjacent passage holes while at the same time facilitating the passage of steam or vapor therethrough.
Other and further objects related to this invention will appear in the course of the following description.